Is Eating Too Much Sugar Harmful to Your Bones?

Yes, it tastes sweet, but sugar has a well-earned reputation of being unhealthy. Diets high in sugar are linked with greater risk for a number of health problems, including heart disease, type 2 diabetes, obesity, and tooth decay. Can it even increase your risk for osteoporosis? You might not think of sugar as being connected with bone health, but there’s evidence that it is.

Sugar, Bone Health, and Osteoporosis

Here’s a frightening statistic. Almost one-third of women in the U.S. will develop osteoporosis at some point in their life and a portion of those who do will end up with an osteoporosis-related fracture. Osteoporosis is characterized by low bone density, bones that are too porous. It’s often a silent disease with few symptoms until the first osteoporosis-related fracture shows up. In later stages, it’s harder to ignore as loss of bone density leads to compression fractures of the vertebral column that manifest as a loss in height and a rounded upper back referred to as a “dowager’s hump.”

Everyone, especially women, should be concerned about bone health. Bone is always remodeling itself, meaning old bone is broken down and new bone is formed. Ideally, when old bone is abolished, an equal amount of new bone replaces it, but as you age, bone breakdown usually occurs faster than it can be replaced. This leads to bones that are weak, brittle, and prone towards fracturing. If you built up strong, dense bones when you were young, you have more bone in reserve and are more protected against osteoporosis.

You probably already know many of the risk factors for osteoporosis:

Family history of osteoporosis

Leading a sedentary lifestyle

Excessive alcohol use

Smoking

Being small-boned or having a low body weight

Being Caucasian or Asian

Being female

As with most health problems, diet plays a role too. Conventionally, physicians recommend getting enough dietary calcium and vitamin D throughout life and doing weight-bearing exercise. Unfortunately, recently research questions whether calcium supplements are beneficial for older women and whether they’re even safe. Still, it’s important to get enough calcium from dietary sources regardless of how old you are. Calcium is important for more than just bone health.

Recently, interest has turned to the role sugar plays in maintaining healthy bones.

Sugar is Everywhere

You find sugar in most packaged products you pick up at the supermarket, in one form or the other. Table sugar is a mixture of two simpler sugars – glucose and fructose. You’ll also see products sweetened with a more concentrated form of fructose – high-fructose corn syrup. If you read the labels of packaged products, you’ll quickly see how many contain this inexpensive sweetener.

What role might sugar play in osteoporosis? At least in animal studies, a diet high in sugar is linked with decreased bone density – but why? One theory is sugar negatively affects calcium balance. When you consume something sweet like a cookie, you excrete more calcium in your urine afterward.

Where does the calcium come from? It’s siphoned from your bones. So, a diet high in sugar may cause calcium loss from bones – not a healthy situation. In addition, a number of studies dating back to the 1990s show calcium changes the mechanical properties of bones – how strong they are and how they function.

Soft Drinks and Bone Density

One of the biggest sources of dietary sugar, especially among young people, is soft drinks. How much sugar does the average soft drink have? Hold on to your seats! A 12-ounce can of soda has around 39 grams of sugar, about half of which is fructose. Since 4 grams of sugar is about a teaspoon, a standard can of soft drink has between 9 and 10 teaspoons of sugar.

Researchers now suspect that fructose blocks the absorption of calcium from your digestive tract. As a result, it lowers your total body stores of calcium and the amount stored in your bones. You need that calcium for strong, fracture-resistant bones. So, a diet high in sugar may reduce calcium absorption and potentially lead to calcium loss from your bones.

In addition, soft drinks are high in phosphoric acid. This creates excess acidity that needs to be neutralized. One way your body neutralizes excess acid is by releasing calcium from inside bones. That’s why you hear so much about the health benefits of an alkaline diet, rich in fruits and vegetables, as opposed to an acidic one, like a diet high in animal products.

Phosphoric acid also interferes with calcium absorption as the phosphorus binds to calcium and makes it harder to absorb. Cola beverages have higher levels of phosphoric acid than clear, carbonated beverages and are the ones most strongly linked with decreased bone density.

This all sounds good in theory, but does it play out in real life? Observational studies show a strong link between soft drink consumption and decreased bone density in women. So, sugar, and particularly sugar and phosphoric acid in soft drinks, is likely harmful to your bones. One more reason to grab a cup of tea! Both black and oolong tea have been linked with higher bone density, possibly due to the high levels of flavonoids in both. Just don’t add sugar to sweeten it! A little Stevia is a better alternative.

Keep in mind that sugar is a source of empty calories and devoid of nutrition. When you eat foods high in sugar, you’re probably getting less bone-protective minerals like calcium and magnesium.

Did You Know Osteoporosis Was Once Uncommon?

Osteoporosis is such a common problem today that we assume it’s always been an issue. Surprisingly, prior to the 19th century, osteoporosis was relatively uncommon – but why? You might assume we’re better at diagnosing it, which is true, but most scientists still believe the increase is very real. The fact that people do less weight-bearing exercise is one explanation, but you also have to look at the American diet. Sugar and soft drinks are also probably a factor as is the amount of salt most people eat these days. Like sugar, sodium increases calcium excretion. Plus, we get less vitamin D on average than we did a century or more ago when more people spent time outdoors.

The Bottom Line

Low levels of calcium, vitamin D, and lack of physical activity at least partially explain why osteoporosis has become such an epidemic, but a high-sugar diet is also likely a factor. It’s another reason to eliminate, or at least cut back, on the amount of sugar in your diet.

References:

J. Nutr. October 1, 1998. vol. 128 no. 10 1807-1810.

Live Science. “The Relationship Between Fructose and Bone Fragility” September 7, 2012.